The goal of the current proposal is to conduct a randomized, comparative, non-inferiority clinical trial that tests the hypothesis that a widely used form of manualized dynamic psychotherapy (supportive expressive psychodynamic therapy) is not inferior to cognitive therapy when implemented in community mental health settings for the treatment of major depressive disorder. Major depressive disorder is a severe and disabling disorder afflicting 7% of individuals in the United States annually and approximately 17% of individuals across their lifetime (Kessler et al., 2005). Over the past 30 years, cognitive therapy (Beck et al., 1979) has become established as the most empirically-validated psychosocial treatment for major depressive disorder (Hollon, Thase, & Markowitz, 2002). At this point in time, extensive efforts are occurring to disseminate cognitive therapy to clinical practice settings. Health systems and managed care entities have begun to accelerate dissemination of cognitive therapy to existing psychotherapists working in community agencies. Despite the large number of studies that have been done on cognitive therapy, one central question relevant to mental health care systems and agencies that has never been addressed is whether or not cognitive therapy provides superior outcomes to the typical form of psychotherapy provided by many community-based psychotherapists. If a standard form of psychotherapy (i.e., psychodynamic therapy) already common in the community produces outcomes that are not inferior to those produced by cognitive therapy, then the extensive amount of funds needed to re-train community therapists in cognitive therapy would be better spent on other quality improvement initiatives including hiring new therapists to help with the understaffing that is prevalent in the community. The Specific Aims of the current proposal are 1) to conduct a randomized non-inferiority trial to compare supportive-expressive psychodynamic therapy and cognitive therapy for patients with major depressive disorder, and 2) to assess the comparative effectiveness of supportive-expressive therapy and cognitive therapy on secondary measures of patient functioning and quality of life. Therapists working in community mental health agencies will be trained in either cognitive therapy or dynamic psychotherapy during the first year of the protocol. In addition, concurrent therapist training procedures will be implemented across the study period in order to retain the appropriate number of therapists throughout the study. Consumers seeking services at two community mental health centers will be randomized to either receive 12 sessions of cognitive therapy or dynamic psychotherapy. All psychotherapy will be provided by therapists employed at the community agency and will take place at the community agency. Consumers diagnosed with major depressive disorder at the mental health agency will be offered participation in the current protocol. Interested consumers will be consented for the study and randomized to treatment. All participants will complete a baseline interview as well as monthly assessments of depressive symptoms, functioning, and quality of life. As part of normal clinic procedures, all consumers will also complete the BASIS-24 at baseline and at each treatment session. We will evaluate whether dynamic psychotherapy is not inferior to cognitive therapy on change from baseline to endpoint of acute treatment in the HAM-D total score. If psychodynamic therapy is not inferior to cognitive therapy, the cost of re-training psychotherapists in cognitive therapy may not be warranted.